The appointment of Jeremiah to the prophet's office

In chapter 1 the prophet is established in his office, to which
he had been appointed by Jehovah, even before his birth, that he
should carry His word unto the nations. But Jeremiah's fears are
immediately manifested. The Lord encourages him by the assurance of
His presence. He puts His words into his mouth, and appoints him
as prophet over the nations to root out and to plant. Two visions
are shewn him, which contain the summary of the prophetic charge
communicated to him, and announce that Jerusalem shall soon be
stricken by the kingdoms of the north. Under these circumstances
Jeremiah is set before a rebellious people, who will strive against
him. Nevertheless he must declare everything; and as the Lord had
before encouraged the prophet, He now adds to the encouragement, in
order to enforce it, a threat in case of disobedience; namely,
that, if through fear he drew back from his commission, the Lord
would become a greater cause of fear, and would break him to pieces
before those of whom he was afraid. But if he fulfilled his
appointed task, Jehovah would be with him. Verses 6-8, 17, 18,
shew the great fearfulness of the prophet's spirit, which needed to
be thus strengthened by Jehovah.